Extraction of Limit Streamlines in 2D Flow Field Using Virtual Boundary

2009 ◽  
Author(s):  
Wenyao Zhang ◽  
Jing Su
Keyword(s):  
Flow Field ◽  
2D Flow ◽  
Virtual Boundary

The Okubo-Weiss criterion in hydrodynamic flows:Geometric aspects and further extension

2022 ◽  
Author(s):  
Bhimsen Shivamoggi ◽  
G Heijst ◽  
Leon Kamp
Keyword(s):  
Flow Field ◽  
Polar Coordinates ◽  
Coriolis Parameter ◽  
Laminar Jet ◽  
Type Criterion ◽  
Burgers Vortex ◽  
2D Flow ◽  
Flow Configurations ◽  
Elliptic Regions ◽  
Oseen Vortex

Abstract The Okubo [5]-Weiss [6] criterion has been extensively used as a diagnostic tool to divide a two-dimensional (2D) hydrodynamical flow field into hyperbolic and elliptic regions and to serve as a useful qualitative guide to the complex quantitative criteria. The Okubo-Weiss criterion is frequently validated on empirical grounds by the results ensuing its application. So, we will explore topological implications into the Okubo-Weiss criterion and show the Okubo-Weiss parameter is, to within a positive multiplicative factor, the negative of the Gaussian curvature of the underlying vorticity manifold. The Okubo-Weiss criterion is reformulated in polar coordinates, and is validated via several examples including the Lamb- Oseen vortex, and the Burgers vortex. These developments are then extended to 2D quasi- geostrophic (QG) flows. The Okubo-Weiss parameter is shown to remain robust under the -plane approximation to the Coriolis parameter. The Okubo-Weiss criterion is shown to be able to separate the 2D flow-field into coherent elliptic structures and hyperbolic flow configurations very well via numerical simulations of quasi-stationary vortices in QG flows. An Okubo-Weiss type criterion is formulated for 3D axisymmetric flows, and is validated via application to the round Landau-Squire Laminar jet flow.

Low Analysis of Steady Flow Field in Mechanical Seal Based on ANSYS

2011 ◽  
Vol 121-126 ◽  
pp. 3352-3355
Author(s):  
Yue Feng Zhu ◽  
De Lin Chen
Keyword(s):  
Flow Field ◽  
Steady Flow ◽  
Mechanical Seal ◽  
The Press ◽  
2D Flow ◽  
Comparison And Analysis ◽  
Velocity Contour

Simulation and analysis of steady and 2D flow field by using ANSYS8.0 and getting the press and velocity contour. omulate the leakage. then through comparison and analysis offering theory evidence for controlling leakage effectively.

Introduction of Virtual Structural Boundary for Collision Force Analysis of Tsunami Drifting Objects in Particle Method

2019 ◽  
Author(s):  
Yasuhiro Aida ◽  
Koichi Masuda ◽  
Tomoki Ikoma ◽  
Hiroaki Eto
Keyword(s):  
Boundary Condition ◽  
Analytical Solution ◽  
Flow Field ◽  
Particle Method ◽  
Force Analysis ◽  
Fluid Force ◽  
Virtual Boundary ◽  
Collision Force ◽  
Structural Boundary ◽  
Particle Boundary

Abstract One of the reasonable methods to analyze the collision force of a tsunami drifting object against a structure is a particle method. However, when both the structure and the drifting body are composed of particles, there are various problems such as particles of the collision object slipping through particles of the structure. Therefore, the authors have constructed a particle method - analytical solution hybrid method which can analyze the collision force of a tsunami drifting object to an elastic member by constructing a structure as a boundary condition acting on a drifting object. However, since this boundary was introduced as a virtual boundary that acts only on drifting particles, the collision force of the tsunami drifting object to the structure can be analyzed, but the fluid force can’t be analyzed. Therefore, in this study, in addition to the boundary condition as the structure, we further reconstructed the collision force and the fluid force as a method that can analyze the collision force and the fluid force simultaneously by setting the mirror particle boundary condition for the fluid particle. By developing this method, it became possible to calculate the collision force in a situation where a stagnation point occurs like a flow field at the front of the wall type structure, and the drifting object is decelerating.

Quasi Two-Dimensional Flow-Adaptive Algorithm for Pneumatic Probe Measurements

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Christian Bartsch ◽  
Magnus Hölle ◽  
Peter Jeschke ◽  
Timo Metzler
Keyword(s):  
Flow Field ◽  
Measurement Data ◽  
Field Conditions ◽  
Measuring System ◽  
Two Dimensional ◽  
Local Flow ◽  
Field Surveys ◽  
Uniform Grids ◽  
2D Flow ◽  
Two Dimensional Flow

The subject of this paper is a flow-adaptive measurement grid algorithm developed for one-dimensional (1D) and two-dimensional (2D) flow field surveys with pneumatic probes in turbomachinery flows. The algorithm automatically determines the distribution and the amount of measurement points needed for an approximation of the pressure distribution within a predefined accuracy. The algorithm is based on transient traverses, conducted back and forth in the circumferential direction. A correction of the dynamic response is applied by deconvolving the transient measurement data using the information embedded in both transient measurements. In consequence, the performance of the algorithm is largely independent of the transient traversing speed and the geometry of the pressure measuring system. Insertion and removal strategies are incorporated in order to reduce measurement points and increase robustness toward differing flow field conditions. The performance of the algorithm is demonstrated for 2D flow field surveys with a pneumatic five-hole probe in an annular cascade wind tunnel. The measurement grid points are automatically adjusted so that a consistent resolution of the flow features is achieved within the measurement domain. Furthermore, the application of the algorithm shows a significant reduction in the number of measurement points. Compared to the measurement duration based on uniform grids, the duration is reduced by at least 7%, while maintaining a high accuracy of the measurement. The purpose of this paper is to demonstrate the performance of measurement grids adapted to local flow field conditions. Consequently, valuable measurement time can be saved without a loss in quality of the data obtained.

scholarly journals 2D Flow Field Analysis by the Exergetic Method

2019 ◽  
Author(s):  
Miguel A. Aguirre ◽  
Sébastien Duplaa ◽  
Xavier Carbonneau
Keyword(s):  
Flow Field ◽  
Field Analysis ◽  
2D Flow ◽  
Flow Field Analysis

scholarly journals FlowVisual: Design and Evaluation of a Visualization Tool for Teaching 2D Flow Field Concepts

2020 ◽  
Author(s):  
Man Wang ◽  
Jun Tao ◽  
Chaoli Wang ◽  
Ching-Kuang Shene ◽  
Seung Hyun Kim
Keyword(s):  
Flow Field ◽  
Visualization Tool ◽  
2D Flow

Quasi 2D Flow-Adaptive Algorithm for Pneumatic Probe Measurements

2016 ◽  
Author(s):  
Christian Bartsch ◽  
Magnus Hölle ◽  
Peter Jeschke ◽  
Timo Metzler
Keyword(s):  
Flow Field ◽  
Dynamic Response ◽  
Pressure Distribution ◽  
Measurement Data ◽  
Field Conditions ◽  
Measuring System ◽  
Local Flow ◽  
Field Surveys ◽  
2D Flow ◽  
Adaptive Measurement

The subject of this paper is a flow-adaptive measurement grid algorithm developed for 1D and 2D flow field surveys with pneumatic probes in turbomachinery flows. The algorithm automatically determines the distribution and the amount of measurement points needed for an approximation of the pressure distribution within a predefined accuracy. The algorithm is based on transient traverses, conducted back and forth in the circumferential direction. The dynamic response of the pressure-measuring system is disregarded during the traverses, which serve to detect changes in the pressure field. In contrast to previous investigations by the authors, a correction of the dynamic response is applied by deconvolving the transient measurement data using the information embedded in both transient measurements. In consequence, the performance of the algorithm is — to a large extent — independent of the transient traversing speed and the geometry of the pressure-measuring system. Insertion and removal strategies are incorporated in order to reduce measurement points and increase robustness towards differing flow field conditions. By approximation of the pressure distribution, the flow-adaptive measurement data is suited for the application of post-processing corrections without any constraints. The performance of the algorithm is demonstrated for 2D flow field surveys with a pneumatic 5-hole probe in an annular cascade wind tunnel. Compared to conventional techniques for data sampling, e.g., uniform measurement grids, the measurement grid points are automatically adjusted so that a consistent resolution of the flow features is achieved within the measurement domain. Furthermore, the application of the algorithm shows a significant reduction in the number of measurement points. Compared to the measurement duration based on uniform grids, the duration is reduced by at least 7%, while maintaining a high accuracy of the measurement. The purpose of this paper is to demonstrate the performance of measurement grids adapted to local flow field conditions. Consequently, valuable measurement time can be saved without a loss in quality of the data obtained.

Numerical Study of the Combined Free-Forced Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium with Heat Generation and Thermal Diffusion

2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad
Keyword(s):  
Mass Transfer ◽  
Flow Field ◽  
Differential Equations ◽  
Forced Convection ◽  
Heat Generation ◽  
Numerical Study ◽  
Porous Plate ◽  
Integration Scheme ◽  
Suction Parameter ◽  
Transfer Flow

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.

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